Just started my course on the power electronics....interesting that the output voltage is function of dutycycle and input...but does frequency not infuluence the circuit at all...how do we determine the minimum frequency needed to maintan the output according to the duty cycle...for example if the frequeny of the PWM is 0.1 Hz and the Ton is 10 %, then the power supply would be on for 1 sec and I think 9 seconds will be quite large time to keep the voltage...capacitor would soon discharge...finally producing....not stable dc..but ripple output.....please help me understand the minimum frequency.....and what is it depending on...? Presently I guess...the value of capacitor in parallel??